Re: jit lock sit-for provokes redisplay provokes imenu

[martin rudalics]

> Rather than increment CHARS_MODIFF separately,
> it should copy the value from MODIFF.
> That way, values of CHARS_MODIFF will be comparable with values
> that were copied from MODIFF.

Yes, but it will deprive you of eventually introducing a variable
SAVE_CHARS_MODIFF and tell whether an insertion/deletion occurred
since the last save because CHARS_MODIFF > SAVE_CHARS_MODIFF.

> Also, instead of setting CHARS_MODIFF explicitly in each place that
> modifies the buffer, modify_region could set it from MODIFF, and
> changing text properties could save and restore it to prevent it from
> being incremented.  That means changes in fewer places, and no need
> for each place that modifies the buffer to know about CHARS_MODIFF.

Perhaps the cleanest solution would be to equip modify_region with an
additional parameter, say preserve_chars_modiff, and do everything in
modify_region.

In the attached patch I tried to follow your suggestions.

*** buffer.c    Tue Jun  6 19:20:40 2006
--- buffer.c    Fri Jul 21 16:00:22 2006
***************
*** 371,376 ****
--- 371,377 ----
    BUF_ZV_BYTE (b) = BEG_BYTE;
    BUF_Z_BYTE (b) = BEG_BYTE;
    BUF_MODIFF (b) = 1;
+   BUF_CHARS_MODIFF (b) = 1;
    BUF_OVERLAY_MODIFF (b) = 1;
    BUF_SAVE_MODIFF (b) = 1;
    BUF_INTERVALS (b) = 0;
***************
*** 1145,1150 ****
--- 1146,1172 ----

    return make_number (BUF_MODIFF (buf));
  }
+ 
+ DEFUN ("buffer-chars-modified-tick", Fbuffer_chars_modified_tick, 
Sbuffer_chars_modified_tick,
+        0, 1, 0,
+        doc: /* Return BUFFER's tick counter, incremented for each 
insert/delete.
+ Each buffer has a tick counter which is incremented each time text in
+ that buffer is inserted or deleted.  It wraps around occasionally.
+ No argument or nil as argument means use current buffer as BUFFER.  */)
+      (buffer)
+      register Lisp_Object buffer;
+ {
+   register struct buffer *buf;
+   if (NILP (buffer))
+     buf = current_buffer;
+   else
+     {
+       CHECK_BUFFER (buffer);
+       buf = XBUFFER (buffer);
+     }
+ 
+   return make_number (BUF_CHARS_MODIFF (buf));
+ }
  
  DEFUN ("rename-buffer", Frename_buffer, Srename_buffer, 1, 2,
         "sRename buffer (to new name): \nP",
***************
*** 6014,6019 ****
--- 6036,6042 ----
    defsubr (&Sbuffer_modified_p);
    defsubr (&Sset_buffer_modified_p);
    defsubr (&Sbuffer_modified_tick);
+   defsubr (&Sbuffer_chars_modified_tick);
    defsubr (&Srename_buffer);
    defsubr (&Sother_buffer);
    defsubr (&Sbuffer_enable_undo);

*** buffer.h    Tue Apr 11 16:24:24 2006
--- buffer.h    Fri Jul 21 15:31:34 2006
***************
*** 82,87 ****
--- 82,90 ----
  /* Modification count.  */
  #define MODIFF (current_buffer->text->modiff)

+ /* Character modification count.  */
+ #define CHARS_MODIFF (current_buffer->text->chars_modiff)
+ 
  /* Overlay modification count.  */
  #define OVERLAY_MODIFF (current_buffer->text->overlay_modiff)

***************
*** 147,152 ****
--- 150,158 ----
  /* Modification count.  */
  #define BUF_MODIFF(buf) ((buf)->text->modiff)

+ /* Character modification count.  */
+ #define BUF_CHARS_MODIFF(buf) ((buf)->text->chars_modiff)
+ 
  /* Modification count as of last visit or save.  */
  #define BUF_SAVE_MODIFF(buf) ((buf)->text->save_modiff)

***************
*** 406,411 ****
--- 412,421 ----
                                   for this buffer.  It is incremented for
                                   each such event, and never otherwise
                                   changed.  */
+     int chars_modiff;         /* This counts insert/delete events
+                                  for this buffer.  It is incremented for
+                                  each such event, and never otherwise
+                                  changed.  */
      int save_modiff;          /* Previous value of modiff, as of last
                                   time buffer visited or saved a file.  */


*** insdel.c    Tue Apr 11 16:24:24 2006
--- insdel.c    Sat Jul 22 09:48:24 2006
***************
*** 1007,1012 ****
--- 1007,1013 ----
       will add up to the right stuff in the undo list.  */
    record_insert (PT, nchars);
    MODIFF++;
+   CHARS_MODIFF = MODIFF;

    bcopy (string, GPT_ADDR, nbytes);

***************
*** 1144,1149 ****
--- 1145,1151 ----

    record_insert (PT, nchars);
    MODIFF++;
+   CHARS_MODIFF = MODIFF;

    GAP_SIZE -= outgoing_nbytes;
    GPT += nchars;
***************
*** 1295,1300 ****
--- 1297,1303 ----

    record_insert (PT, nchars);
    MODIFF++;
+   CHARS_MODIFF = MODIFF;

    GAP_SIZE -= outgoing_nbytes;
    GPT += nchars;
***************
*** 1403,1408 ****
--- 1406,1412 ----
    if (len == 0)
      evaporate_overlays (from);
    MODIFF++;
+   CHARS_MODIFF = MODIFF;
  }

  /* Like adjust_after_replace, but doesn't require PREV_TEXT.
***************
*** 1453,1458 ****
--- 1457,1463 ----
    if (len == 0)
      evaporate_overlays (from);
    MODIFF++;
+   CHARS_MODIFF = MODIFF;
  }

  /* Record undo information, adjust markers and position keepers for an
***************
*** 1645,1650 ****
--- 1650,1656 ----
    CHECK_MARKERS ();

    MODIFF++;
+   CHARS_MODIFF = MODIFF;
    UNGCPRO;

    signal_after_change (from, nchars_del, GPT - from);
***************
*** 1769,1774 ****
--- 1775,1781 ----
    CHECK_MARKERS ();

    MODIFF++;
+   CHARS_MODIFF = MODIFF;
  }
  
  /* Delete characters in current buffer
***************
*** 1950,1955 ****
--- 1957,1963 ----
    if (! EQ (current_buffer->undo_list, Qt))
      record_delete (from, deletion);
    MODIFF++;
+   CHARS_MODIFF = MODIFF;

    /* Relocate point as if it were a marker.  */
    if (from < PT)
***************
*** 2009,2014 ****
--- 2017,2023 ----
    if (MODIFF <= SAVE_MODIFF)
      record_first_change ();
    MODIFF++;
+   CHARS_MODIFF = MODIFF;

    buffer->point_before_scroll = Qnil;


*** textprop.c  Sun Jul  2 09:50:00 2006
--- textprop.c  Sat Jul 22 10:44:34 2006
***************
*** 1247,1253 ****
      }

    if (BUFFERP (object))
!     modify_region (XBUFFER (object), XINT (start), XINT (end));

    /* We are at the beginning of interval I, with LEN chars to scan.  */
    for (;;)
--- 1247,1257 ----
      }

    if (BUFFERP (object))
!     {
!       int save_chars_modiff = CHARS_MODIFF;
!       modify_region (XBUFFER (object), XINT (start), XINT (end));
!       CHARS_MODIFF = save_chars_modiff;
!     }

    /* We are at the beginning of interval I, with LEN chars to scan.  */
    for (;;)
***************
*** 1387,1393 ****
      }

    if (BUFFERP (object))
!     modify_region (XBUFFER (object), XINT (start), XINT (end));

    set_text_properties_1 (start, end, properties, object, i);

--- 1391,1401 ----
      }

    if (BUFFERP (object))
!     {
!       int save_chars_modiff = CHARS_MODIFF;
!       modify_region (XBUFFER (object), XINT (start), XINT (end));
!       CHARS_MODIFF = save_chars_modiff;
!     }

    set_text_properties_1 (start, end, properties, object, i);

***************
*** 1535,1541 ****
      }

    if (BUFFERP (object))
!     modify_region (XBUFFER (object), XINT (start), XINT (end));

    /* We are at the beginning of an interval, with len to scan */
    for (;;)
--- 1543,1553 ----
      }

    if (BUFFERP (object))
!     {
!       int save_chars_modiff = CHARS_MODIFF;
!       modify_region (XBUFFER (object), XINT (start), XINT (end));
!       CHARS_MODIFF = save_chars_modiff;
!     }

    /* We are at the beginning of an interval, with len to scan */
    for (;;)
***************
*** 1649,1655 ****
          if (LENGTH (i) == len)
            {
              if (!modified && BUFFERP (object))
!               modify_region (XBUFFER (object), XINT (start), XINT (end));
              remove_properties (Qnil, properties, i, object);
              if (BUFFERP (object))
                signal_after_change (XINT (start), XINT (end) - XINT (start),
--- 1661,1671 ----
          if (LENGTH (i) == len)
            {
              if (!modified && BUFFERP (object))
!               {
!                 int save_chars_modiff = CHARS_MODIFF;
!                 modify_region (XBUFFER (object), XINT (start), XINT (end));
!                 CHARS_MODIFF = save_chars_modiff;
!               }
              remove_properties (Qnil, properties, i, object);
              if (BUFFERP (object))
                signal_after_change (XINT (start), XINT (end) - XINT (start),
***************
*** 1662,1668 ****
          i = split_interval_left (i, len);
          copy_properties (unchanged, i);
          if (!modified && BUFFERP (object))
!           modify_region (XBUFFER (object), XINT (start), XINT (end));
          remove_properties (Qnil, properties, i, object);
          if (BUFFERP (object))
            signal_after_change (XINT (start), XINT (end) - XINT (start),
--- 1678,1688 ----
          i = split_interval_left (i, len);
          copy_properties (unchanged, i);
          if (!modified && BUFFERP (object))
!           {
!             int save_chars_modiff = CHARS_MODIFF;
!             modify_region (XBUFFER (object), XINT (start), XINT (end));
!             CHARS_MODIFF = save_chars_modiff;
!           }
          remove_properties (Qnil, properties, i, object);
          if (BUFFERP (object))
            signal_after_change (XINT (start), XINT (end) - XINT (start),
***************
*** 1673,1679 ****
        if (interval_has_some_properties_list (properties, i))
        {
          if (!modified && BUFFERP (object))
!           modify_region (XBUFFER (object), XINT (start), XINT (end));
          remove_properties (Qnil, properties, i, object);
          modified = 1;
        }
--- 1693,1703 ----
        if (interval_has_some_properties_list (properties, i))
        {
          if (!modified && BUFFERP (object))
!           {
!             int save_chars_modiff = CHARS_MODIFF;
!             modify_region (XBUFFER (object), XINT (start), XINT (end));
!             CHARS_MODIFF = save_chars_modiff;
!           }
          remove_properties (Qnil, properties, i, object);
          modified = 1;
        }

*** imenu.el    Mon May  1 10:08:52 2006
--- imenu.el    Fri Jul 21 16:30:38 2006
***************
*** 968,982 ****
  (defvar imenu-buffer-menubar nil)

  (defvar imenu-menubar-modified-tick 0
!   "The value of (buffer-modified-tick) as of last call to 
`imenu-update-menubar'.")
  (make-variable-buffer-local 'imenu-menubar-modified-tick)

  (defun imenu-update-menubar ()
    (when (and (current-local-map)
             (keymapp (lookup-key (current-local-map) [menu-bar index]))
!            (not (eq (buffer-modified-tick)
                      imenu-menubar-modified-tick)))
!     (setq imenu-menubar-modified-tick (buffer-modified-tick))
      (let ((index-alist (imenu--make-index-alist t)))
        ;; Don't bother updating if the index-alist has not changed
        ;; since the last time we did it.
--- 968,982 ----
  (defvar imenu-buffer-menubar nil)

  (defvar imenu-menubar-modified-tick 0
!   "The value of (buffer-chars-modified-tick) as of last call to 
`imenu-update-menubar'.")
  (make-variable-buffer-local 'imenu-menubar-modified-tick)

  (defun imenu-update-menubar ()
    (when (and (current-local-map)
             (keymapp (lookup-key (current-local-map) [menu-bar index]))
!            (not (eq (buffer-chars-modified-tick)
                      imenu-menubar-modified-tick)))
!     (setq imenu-menubar-modified-tick (buffer-chars-modified-tick))
      (let ((index-alist (imenu--make-index-alist t)))
        ;; Don't bother updating if the index-alist has not changed
        ;; since the last time we did it.